Hey guys, please forgive a dumb question. On a truck with anti-lock braking system on 4 wheels, is the inside or outside wheel of duals the one that has the brakes? Or do all four rear wheels have brakes but the ABS only apply to two, or does the front have anything to do with it and the ABS apply to the rear 4 wheels?
I just don't have a clue, and you can stop laughing now!
gypsy
Racerguy said
08:46 PM Oct 12, 2008
Gypsy, there are no dumb questions. The rear brake drum or rotor on each side of rear axle contains the brakes for the rear wheels(1 for each side) The 4 wheel anti-lock system controls both the rear brakes and the front brakes. Hope that helps.
Roz said
05:39 AM Oct 13, 2008
Automatic Braking Systems (ABS) on different vehicles have different functions, but the main function is to keep wheels from locking up and causing a skid situation.
ABS has two components - modulators and sensors. There are various combinations of these two, particularly on large semi-trailers and I would suspect available on large fivers.
The sensors are on the wheel ends. Their purpose is to sense when the wheels are not turning at the speed you are traveling which causes a skid. This information is transferred to the modulator(s).
There can be one modulator for two axles or a modulator for each axle. (better) The modulator causes to the brakes to release enough to allow the "skidding tire(s) to again roll instead of sliding.
With air brakes, this is accomplished by the modulator dumping air. With non-air brakes it simply releases the brakes for a fraction of a second accomplishing the same result. Then the brakes are reapplied. Prior to ABS, this was accomplished by "pumping" the brake pedal.
If you have two trailer axles, and a 2S/1M system, the sensors on one of the axles relays the skid and the modulator "pumps" the brakes for both axles. A 4S/1M would have a sensors on wheel ends of both axles so that any wheel that skids would activate the pumping on all tires.
An upgrade is a 4S/2M system which would activate only the axle with skidding tires.
This is much more than necessary to know, but you can ask the manufacturer what type of ABS is on a vehicle and realize which is better.
ABS is a wonderful technology originally developed for large aircraft!
I just don't have a clue, and you can stop laughing now!
gypsy
ABS has two components - modulators and sensors. There are various combinations of these two, particularly on large semi-trailers and I would suspect available on large fivers.
The sensors are on the wheel ends. Their purpose is to sense when the wheels are not turning at the speed you are traveling which causes a skid. This information is transferred to the modulator(s).
There can be one modulator for two axles or a modulator for each axle. (better) The modulator causes to the brakes to release enough to allow the "skidding tire(s) to again roll instead of sliding.
With air brakes, this is accomplished by the modulator dumping air. With non-air brakes it simply releases the brakes for a fraction of a second accomplishing the same result. Then the brakes are reapplied. Prior to ABS, this was accomplished by "pumping" the brake pedal.
If you have two trailer axles, and a 2S/1M system, the sensors on one of the axles relays the skid and the modulator "pumps" the brakes for both axles. A 4S/1M would have a sensors on wheel ends of both axles so that any wheel that skids would activate the pumping on all tires.
An upgrade is a 4S/2M system which would activate only the axle with skidding tires.
This is much more than necessary to know, but you can ask the manufacturer what type of ABS is on a vehicle and realize which is better.
ABS is a wonderful technology originally developed for large aircraft!